[22.04] Effect of Negative Ions on the Conductivity of Titan's Lower Atmosphere

In an earlier paper, Borucki et al (1987) calculated the
electrical conductivity and electrical charge on aerosols in
Titanís atmosphere due to the ionization by galactic cosmic
rays and electron precipitation from Saturnís magnetosphere.
The lower atmosphere was predicted to be substantially more
conducting than the atmospheres of Earth and Venus because
of the high concentration of free electrons. The prediction
of a high conductivity is based on the lack of
electrophillic species which form negative ions with low
mobility and which reduce the number of free electrons. At
that time, no molecular species capable of forming negative
ions in concentrations sufficient to perturb the atmospheric
conductivity were identified. Recently, E. Bakes and her
colleagues have been investigating the formation of
nitrogenous macromolecules using quantum mechanical methods.
Their calculations indicate that the molecules will be
highly electrophillic and are likely to be present in the
atmosphere at mixing ratios of order 10-7. This mixing ratio
is sufficiently large that a substantial reduction in the
conductivity is expected at altitudes below 100 km. Revision
of the atmospheric model to accommodate the presence of
negative ions and to increase the fidelity of the modeling
will be described.